Drought Stress Described by Transcriptional Responses of Picea Abies (L.) H. Karst. under Pathogen Heterobasidion Parviporum Attack

The major threats to the sustainable supply of forest tree products are adverse climate, pests and diseases. Climate change, exemplified by increased drought, poses a unique threat to global forest health. This is attributed to the unpredictable behavior of forest pathosystems, which can favor fungal pathogens over the host under persistent drought stress conditions in the future. Currently, the effects of drought on tree resistance against pathogens are hypothetical, thus research is needed to identify these correlations. Norway spruce (Picea abies (L.) H. Karst.) is one of the most economically important tree species in Europe and is considered highly vulnerable to changes in climate. Dedicated experiments to investigate how disturbances will affect the Norway spruce—Heterobasidion sp. pathosystem are important, in order to develop different strategies to limit the spread of H. annosum s.l. under the predicted climate change. Here, we report a transcriptional study to compare Norway spruce gene expressions to evaluate the effects of water availability and the infection of Heterobasidion parviporum. We performed inoculation studies of three-year-old saplings in a greenhouse (purchased from a nursery). Norway spruce saplings were treated in either high (+) or low (−) water groups: high water group received double the water amount than the low water group. RNA was extracted and sequenced. Similarly, we quantified gene expression levels of candidate genes in biotic stress and jasmonic acid (JA) signaling pathways using qRT-PCR, through which we discovered a unique preferential defense response of H. parviporum-infected Norway spruce under drought stress at the molecular level. Disturbances related to water availability, especially low water conditions can have negative effects on the tree host and benefit the infection ability of the pathogens in the host. From our RNA-seq analysis, 114 differentially expressed gene regions were identified between high (+) and low (−) water groups under pathogen attack. None of these gene pathways were identified to be differentially expressed from both non-treated and mock-control treatments between high (+) and low (−) water groups. Finally, only four genes were found to be associated with drought in all treatments.

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Drought Stress Described by Transcriptional Responses of Picea Abies under Pathogen Heterobasidion Parviporum Attack

10.20944/preprints202109.0224.v1 ◽

2021 ◽

Author(s):

Xenia Hao-Yi Yeoh ◽

Blessing Durodola ◽

Kathrin Blumenstein ◽

Eeva Terhonen

Keyword(s):

Climate Change ◽

Drought Stress ◽

Picea Abies ◽

Norway Spruce ◽

Water Availability ◽

Differentially Expressed Gene ◽

Differentially Expressed ◽

Gene Expressions ◽

Transcriptional Responses ◽

Water Group

The major threats to the sustainable supply of forest tree products are adverse climate, pests and diseases. Climate change, exemplified by increased drought, poses a unique threat to global forest health. This is attributed to the unpredictable behavior of forest pathosystems, which can favor fungal pathogens over the host under persistent drought stress conditions in the future. Currently, the effects of drought on tree resistance against pathogens are hypothetical, thus research is needed to identify these correlations. Norway spruce (Picea abies) is one of the most economically important tree species in Europe, and is considered highly vulnerable to changes in climate. Dedicated experiments to investigate how disturbances will affect the Norway spruce - Heterobasidion sp. pathosystem are important, in order to develop different strategies to limit the spread of H. annosum s.l. under the predicted climate change. Here, we report a transcriptional study to compare Norway spruce gene expressions to evaluate the effects of water availability and the infection of Heterobasidion parviporum. We performed inoculation studies of three-year-old saplings in a greenhouse (purchased from a nursery). Norway spruce saplings were treated in either high (+) or low (-) water groups: high water group received double the water amount than the low water group. RNA was extracted and sequenced. Similarly, we quantified gene expression levels of candidate genes in biotic stress and jasmonic acid (JA) signaling pathways using qRT-PCR, through which we discovered a unique preferential defense response of H. parviporum-infected Norway spruce under drought stress at the molecular level. Disturbances related to water availability, especially low water conditions can have negative effects on the tree host and benefit the infection ability of the pathogens in the host. From our RNA-seq analysis, 114 differentially expressed gene regions were identified between high (+) and low (-) water groups under pathogen attack. None of these gene pathways were identified to be differentially expressed from both non-treated and mock-control treatments between high (+) and low (-) water groups. Finally, only four genes were found to be associated with drought in all treatments.

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Low Water Availability Increases Necrosis in Picea abies after Artificial Inoculation with Fungal Root Rot Pathogens Heterobasidion parviporum and Heterobasidion annosum

Forests ◽

10.3390/f10010055 ◽

2019 ◽

Vol 10 (1) ◽

pp. 55 ◽

Cited By ~ 2

Author(s):

Eeva Terhonen ◽

Gitta Langer ◽

Johanna Bußkamp ◽

David Rӑscuţoi ◽

Kathrin Blumenstein

Keyword(s):

Picea Abies ◽

Norway Spruce ◽

Water Availability ◽

High Water ◽

Climatic Conditions ◽

Heterobasidion Annosum ◽

Economic Losses ◽

Negative Effects ◽

Water Group ◽

Horizontal Length

Research Highlights: Dedicated experiments to investigate how disturbances will affect Heterobasidion sp.—Norway spruce pathosystems are important, in order to develop different strategies to limit the spread of Heterobasidion annosum s.l. under the predicted climate change. Here, we report on a greenhouse experiment to evaluate the effects of water availability on the infection severity of Heterobasidion parviporum or Heterobasidion annosum, respectively, on Picea abies saplings. Background and Objectives: Changes in climatic conditions and intense logging will continue to promote H. annosum s.l. in conifer forests, increasing annual economic losses. Thus, our aim was to test if disease severity in Norway spruce was greater after infection with H. parviporum or H. annosum in low water availability conditions, compared to seedlings with high water availability. Materials and Methods: We performed inoculation studies of three-year-old saplings in a greenhouse. Saplings were treated as high (+) or low (−) water groups: High water group received double the water amount than the low water group. The necrosis observed after pathogen inoculation was measured and analyzed. Results: The seedling growth was negatively influenced in the lower water group. In addition, the water availability enhanced the necrosis length of H. parviporum in phloem and sapwood (vertical length) in the low water group. H. annosum benefited only in horizontal length in the phloem. Conclusions: Disturbances related to water availability, especially low water conditions, can have negative effects on the tree host and benefit the infection ability of the pathogens in the host.

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Comparing transcriptional responses to Fusarium crown rot in wheat and barley identified an important relationship between disease resistance and drought tolerance

BMC Plant Biology ◽

10.1186/s12870-020-02818-1 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Z. Y. Su ◽

J. J. Powell ◽

S. Gao ◽

M. Zhou ◽

C. Liu

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Crown Rot ◽

Differentially Expressed ◽

Transcriptional Responses ◽

Drought Treatment ◽

Crop Species ◽

Fusarium Crown Rot ◽

Important Relationship ◽

The Impact

Abstract Background Fusarium crown rot (FCR) is a chronic disease in cereal production worldwide. The impact of this disease is highly environmentally dependant and significant yield losses occur mainly in drought-affected crops. Results In the study reported here, we evaluated possible relationships between genes conferring FCR resistance and drought tolerance using two approaches. The first approach studied FCR induced differentially expressed genes (DEGs) targeting two barley and one wheat loci against a panel of genes curated from the literature based on known functions in drought tolerance. Of the 149 curated genes, 61.0% were responsive to FCR infection across the three loci. The second approach was a comparison of the global DEGs induced by FCR infection with the global transcriptomic responses under drought in wheat. This analysis found that approximately 48.0% of the DEGs detected one week following drought treatment and 74.4% of the DEGs detected three weeks following drought treatment were also differentially expressed between the susceptible and resistant isolines under FCR infection at one or more timepoints. As for the results from the first approach, the vast majority of common DEGs were downregulated under drought and expressed more highly in the resistant isoline than the sensitive isoline under FCR infection. Conclusions Results from this study suggest that the resistant isoline in wheat was experiencing less drought stress, which could contribute to the stronger defence response than the sensitive isoline. However, most of the genes induced by drought stress in barley were more highly expressed in the susceptible isolines than the resistant isolines under infection, indicating that genes conferring drought tolerance and FCR resistance may interact differently between these two crop species. Nevertheless, the strong relationship between FCR resistance and drought responsiveness provides further evidence indicating the possibility to enhance FCR resistance by manipulating genes conferring drought tolerance.

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Impacts of European spruce bark beetle infestations on Norway spruce BVOC emissions

10.5194/egusphere-egu21-7624 ◽

2021 ◽

Author(s):

Erica Jaakkola ◽

Anna Maria Jönsson ◽

Per-Ola Olsson ◽

Maj-Lena Linderson ◽

Thomas Holst

Keyword(s):

Climate Change ◽

Drought Stress ◽

Norway Spruce ◽

Bark Beetle ◽

Bark Beetles ◽

Atmospheric Environment ◽

Strong Increase ◽

Healthy Tree ◽

Spruce Bark Beetle ◽

Spruce Bark

Tree killing by spruce bark beetles (Ips typographus) is one of the main disturbances to Norway spruce (Picea abies) forests in Europe and the risk of outbreaks is amplified by climate change with effects such as increased risk of storm felling, tree drought stress and an additional generation of spruce bark beetles per year[1]. The warm and dry&#160;summer of&#160;2018 triggered large outbreaks in Sweden, the increased outbreaks are still ongoing and affected&#160;about 8 million m3&#160;forest&#160;in 2020[2]. This is the so&#160;far highest record of trees killed by the spruce bark beetle in a single year in Sweden[2]. In&#160;1990-2010,&#160;the spruce bark beetle killed on&#160;average&#160;150 000 m3&#160;forest per year in southern Sweden[3]. Bark beetles normally seek and attack Norway spruces with lowered defense, i.e. trees that are wind-felled or experience prolonged drought stress[4]. However, as the number of bark beetle outbreaks increase, the risk of attacks on healthy trees also increase[5]. This causes a higher threat to forest industry, and lowers the possibilities to mitigate climate change in terms of potential decreases in carbon uptake if the forests die[4,5]. Norway spruce trees normally defend themselves by drenching the beetles in resin[6]. The resin in turn contains different biogenic volatile organic compounds (BVOCs), which can vary if the spruce is attacked by bark beetles or not [4,6]. The most abundant group of terpenoids (isoprene, monoterpenes and sesquiterpenes), is most commonly emitted from conifers, such as Norway spruce[7,8]. The aim of this study was to enable a better understanding of the direct defense mechanisms of spruce trees by&#160;quantifying BVOC emissions and its composition&#160;from individual&#160;trees under attackTo analyze the bark beetles&#8217; impact on Norway spruce trees a method was developed using tree trunk chambers and adsorbent tubes. This enables direct measurements of the production of BVOCs from individual trees. Three different sites in Sweden, with different environmental conditions were used for the study and samples were collected throughout the growing season of 2019. After sampling, the tubes were analyzed in a lab using automated thermal desorption coupled to a gas chromatograph and a mass spectrometer to identify BVOC species and their quantity.The preliminary results show a strong increase in BVOC emissions from a healthy tree that became infested during the data collection. The finalized results expect to enable better understanding of how spruce trees are affected by insect stress from bark beetles, and if bark beetle infestation will potentially result in increased carbon emission in the form of BVOCs.References[1] J&#246;nsson et al. (2012). Agricultural and Forest Meteorology 166: 188&#8211;200 [2] Skogsstyrelsen, (2020). https://via.tt.se/pressmeddelande/miljontals-granar-dodades-av-granbarkborren-2020?publisherId=415163&releaseId=3288473 [3] Marini et al. (2017). Ecography, 40(12), 1426&#8211;1435. [4] Raffa (1991). Photochemical induction by herbivores. pp. 245-276 [5] Seidl, et al. (2014). Nature Climate Change,&#160;4(9), 806-810. [6] Ghimire, et al. (2016).&#160;Atmospheric Environment,&#160;126, 145-152. [7] Niinemets, U. and Monson, R. (2013). ISBN 978-94-007-6606-8 [8] Kesselmeier, J. and Staudt, M. (1999). Journal of Atmospheric Chemistry, 33(1), pp.23-88

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The physiology of drought stress in grapevine: towards an integrative definition of drought tolerance

Journal of Experimental Botany ◽

10.1093/jxb/eraa245 ◽

2020 ◽

Vol 71 (16) ◽

pp. 4658-4676 ◽

Cited By ~ 6

Author(s):

Gregory A Gambetta ◽

Jose Carlos Herrera ◽

Silvina Dayer ◽

Quishuo Feng ◽

Uri Hochberg ◽

...

Keyword(s):

Climate Change ◽

Drought Stress ◽

Drought Tolerance ◽

Water Availability ◽

Economic Importance ◽

Fruit Crop ◽

Crop Varieties ◽

Drought Tolerant ◽

Definition Of ◽

The Impact

Abstract Water availability is arguably the most important environmental factor limiting crop growth and productivity. Erratic precipitation patterns and increased temperatures resulting from climate change will likely make drought events more frequent in many regions, increasing the demand on freshwater resources and creating major challenges for agriculture. Addressing these challenges through increased irrigation is not always a sustainable solution so there is a growing need to identify and/or breed drought-tolerant crop varieties in order to maintain sustainability in the context of climate change. Grapevine (Vitis vinifera), a major fruit crop of economic importance, has emerged as a model perennial fruit crop for the study of drought tolerance. This review synthesizes the most recent results on grapevine drought responses, the impact of water deficit on fruit yield and composition, and the identification of drought-tolerant varieties. Given the existing gaps in our knowledge of the mechanisms underlying grapevine drought responses, we aim to answer the following question: how can we move towards a more integrative definition of grapevine drought tolerance?

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Effects of climate change on evapotranspiration and soil water availability in Norway spruce forests in southern Finland: an ecosystem model based approach

Ecohydrology ◽

10.1002/eco.276 ◽

2011 ◽

Vol 6 (1) ◽

pp. 51-63 ◽

Cited By ~ 13

Author(s):

Zhen-Ming Ge ◽

Seppo Kellomäki ◽

Xiao Zhou ◽

Kai-Yun Wang ◽

Heli Peltola ◽

...

Keyword(s):

Climate Change ◽

Soil Water ◽

Norway Spruce ◽

Water Availability ◽

Ecosystem Model ◽

Soil Water Availability ◽

Spruce Forests ◽

Model Based

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The effects of slightly elevated ozone concentrations and mild drought stress on the physiology and growth of Norway spruce, Picea abies (L.) Karst. and beech, Fagus sylvatica L., in open-top chambers

New Phytologist ◽

10.1111/j.1469-8137.1994.tb04031.x ◽

1994 ◽

Vol 128 (4) ◽

pp. 671-678 ◽

Cited By ~ 23

Author(s):

DIDIER THIEC ◽

MARTIN DIXON ◽

JEAN PIERRE GARREC

Keyword(s):

Drought Stress ◽

Picea Abies ◽

Norway Spruce ◽

Fagus Sylvatica ◽

Open Top Chambers ◽

Ozone Concentrations ◽

Elevated Ozone ◽

Fagus Sylvatica L ◽

Mild Drought

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The Impact of Drought in Plant Metabolism: How to Exploit Tolerance Mechanisms to Increase Crop Production

Applied Sciences ◽

10.3390/app10165692 ◽

2020 ◽

Vol 10 (16) ◽

pp. 5692 ◽

Cited By ~ 4

Author(s):

Dhriti Kapoor ◽

Savita Bhardwaj ◽

Marco Landi ◽

Arti Sharma ◽

Muthusamy Ramakrishnan ◽

...

Keyword(s):

Climate Change ◽

Drought Stress ◽

Water Availability ◽

Arable Land ◽

Ecological Niches ◽

Antioxidant Systems ◽

Crop Species ◽

Change Factors ◽

The Impact ◽

Stimulation Of

Plants are often exposed to unfavorable environmental conditions, for instance abiotic stresses, which dramatically alter distribution of plant species among ecological niches and limit the yields of crop species. Among these, drought stress is one of the most impacting factors which alter seriously the plant physiology, finally leading to the decline of the crop productivity. Drought stress causes in plants a set of morpho-anatomical, physiological and biochemical changes, mainly addressed to limit the loss of water by transpiration with the attempt to increase the plant water use efficiency. The stomata closure, one of the first consistent reactions observed under drought, results in a series of consequent physiological/biochemical adjustments aimed at balancing the photosynthetic process as well as at enhancing the plant defense barriers against drought-promoted stress (e.g., stimulation of antioxidant systems, accumulation of osmolytes and stimulation of aquaporin synthesis), all representing an attempt by the plant to overcome the unfavorable period of limited water availability. In view of the severe changes in water availability imposed by climate change factors and considering the increasing human population, it is therefore of outmost importance to highlight: (i) how plants react to drought; (ii) the mechanisms of tolerance exhibited by some species/cultivars; and (iii) the techniques aimed at increasing the tolerance of crop species against limited water availability. All these aspects are necessary to respond to the continuously increasing demand for food, which unfortunately parallels the loss of arable land due to changes in rainfall dynamics and prolonged period of drought provoked by climate change factors. This review summarizes the most updated findings on the impact of drought stress on plant morphological, biochemical and physiological features and highlights plant mechanisms of tolerance which could be exploited to increase the plant capability to survive under limited water availability. In addition, possible applicative strategies to help the plant in counteracting unfavorable drought periods are also discussed.

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